scholarly journals The Evaluation of Air Blowing Method of Variable-Air-Conditioning-System using Coanda Effect by Computational Fluid Dynamics

2019 ◽  
Vol 294 ◽  
pp. 012058
Author(s):  
H Sakakibara ◽  
T Akimoto ◽  
H Igarashi ◽  
S Nakamura ◽  
M Kimura
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Air Conditioning ◽  
Coanda Effect ◽  
Air Conditioning System ◽  
Air Blowing ◽  
Coandǎ Effect

scholarly journals The Examination of Air Blowing Method and Thermal Comfort of Variable Air Conditioning System using Coanda Effect

2019 ◽  
Vol 111 ◽  
pp. 01079
Author(s):  
Hikari Sakakibara ◽  
Takashi Akimoto ◽  
Hitomi Igarashi ◽  
Shunsuke Nakamura ◽  
Madoka Kimura
Keyword(s):  
Thermal Comfort ◽  
Air Conditioning ◽  
Air Flow ◽  
Building Design ◽  
Upper Body ◽  
Coanda Effect ◽  
Subjective Perception ◽  
Air Conditioning System ◽  
Air Blowing ◽  
Coandǎ Effect

The “Strategic Energy Plan” implemented by the Cabinet of Japan in 2014 strives for zero energy building design for typical new construction by 2030. The present study focuses on a ductless and variable air conditioning system, using the Coanda effect, with the aim of reducing fan power, and saving of resources by reducing the space between the ceiling. In this study, we examined the air blowing method and evaluated thermal comfort using computational fluid dynamics as well as subjective perception of coolness in a midsize office. A draft zone was reduced by extending the interval between conditioned air outlets. However, if the extension of throw length was excessive, hot space would be formed near the air outlets, and there would be a risk of impacting thermal comfort. Moreover, we confirmed that the thermal comfort was generally favourable. In particular, perceived thermal comfort was better at the position in the office where the air flow landed on the upper body of the subjects. On the other hand, it decreased when the influence of the air flow was small, and at the point where air flow landed on the lower body of the subjects.

Humidity Distribution Simulation of Passenger Vehicle Cabin

2013 ◽  
Vol 291-294 ◽  
pp. 1880-1883
Author(s):  
Li Ping Xiang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Air Conditioning ◽  
Passenger Vehicle ◽  
Air Conditioning System ◽  
Moisture Effect ◽  
Vehicle Cabin ◽  
Hygienic Standard ◽  
Computational Fluid Dynamics Cfd ◽  
Passenger Cabin

A numerical model to improve the air-conditioning system of vehicle cabin taking into the cabin air moisture and its transport by the airflow within the enclosure cabin is described. An efficient computational fluid dynamics(CFD) technique is using the “realisable” model. The temperature and humidity fields in the passenger cabin are investigated individually under having or no body moisture. The temperature in the vehicle cabin taking into account human moisture is lower than no taking into account moisture 0.5 °C. The human dispersing moisture effect significantly on the humidity, which lead to the humidity is elevating and the humidity in vehicle cabin is corresponded hygienic standard.

scholarly journals Theoretical Modeling, Design and Simulation of an Innovative Diverting Valve Based on Coanda Effect

Fluids ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 103
Author(s):  
Giancarlo Comes ◽  
Carlo Cravero
Keyword(s):  
Fluid Dynamics ◽  
Mathematical Model ◽  
Computational Fluid Dynamics ◽  
Additive Manufacturing ◽  
Water Flow ◽  
Coanda Effect ◽  
Geometrical Parameters ◽  
Convex Wall ◽  
Fluidic Device ◽  
Coandǎ Effect

The present work is focused on the study of an innovative fluidic device. It consists of a two-ways diverter valve able to elaborate an inlet water flow and divert it through one of the two outlets without moving parts but as a result of a fluctuation of pressure induced by two actuation ports, or channels. Such apparatus is named Attachment Bi-Stable Diverter (ABD) and is able to work with the effect of the fluid adhesion to a convex wall adjacent to it, this phenomenon is known as Coanda Effect; it generates the force responsible for the fluid attachment and the consequent deviation. The main purpose of this work is to develop a knowhow for the design and development of such particular device. A mathematical model for the ABD has been developed and used to find the relationships between the geometrical parameters and the operative conditions. A configuration has been designed, simulated with a computational fluid dynamics approach. A prototype has been printed with and additive manufacturing printer and tested in laboratory to check the effective working point of the device.

Effect of Air Conditioning Position on Thermal Comfort in the Floor Air Conditioning System

2014 ◽  
Vol 493 ◽  
pp. 74-79
Author(s):  
Y.A. Sabtalistia ◽  
S.N.N. Ekasiwi ◽  
B. Iskandriawan
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Energy Consumption ◽  
Thermal Comfort ◽  
Energy Efficient ◽  
Air Conditioning ◽  
Air Conditioning System ◽  
Air Supply ◽  
Air Conditioning Systems ◽  
Air Diffusion

Energy consumption for air conditioning systems (air conditioning system) increased along with the increasing need for fresh air and comfortable in the room especially apartments. FAC system (Floor Air Conditioning) is growing because it is more energy efficient than CAC (Ceiling Air Conditioning) system. However, the position of the AC supply is on the lower level at the FAC system causes draft discomfort becomes greater as air supply closer to the occupants so that thermal comfort can be reduced. Heat mixture of windows, exterior walls, kitchen, and occupants in the studio apartment affect thermal comfort in the room too.This study aims to determine the position of the AC supply which has the best thermal comfort of FAC system in the studio apartment. It can be done by analyzing ADPI (Air Diffusion Performance Index), the distribution of air temperature, wind speed, RH (Relative Humidity), and DR (Draft Risk) to change the position of the AC supply supported by CFD (Computational Fluid Dynamics) simulation.This result prove that AC position 2 (on wall near the kitchen) is more comfortable than AC position 1 (on the bathroom wall) because AC position 2 away from occupied areas, thereby reducing the occurrence of draught discomfort.

scholarly journals Simulation Study of Air Conditioning System Location in Commercial Kitchen

2020 ◽  
Vol 10 (10) ◽  
pp. 57-61
Author(s):  
Mohammed Juma Al Areimi ◽  
Anbu Clemensis Johnson
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Comparative Analysis ◽  
Air Conditioning ◽  
Side Wall ◽  
Air Conditioning System ◽  
Cooking Process ◽  
Summer Temperatures ◽  
Air Circulation ◽  
Very High

Working in a commercial kitchen in restaurants and hotels is physically challenging. In the Middle East, summer temperatures are very high and require proper ventilation and air conditioning for comfortable working. In the current study a typical kitchen with dimensions 5 m × 4 m × 3 m, with heat source and range hood is modelled using computational fluid dynamics software. A comparative analysis was conducted on the location of the air conditioning system in the kitchen space. The investigated locations of the air conditioning system were on the kitchen side wall and ceiling. The results of the simulation showed that placing the air conditioning system in the ceiling at the centre of the kitchen produced better air circulation. The air flow close to the hood had sufficient velocity to remove heat, contaminants and CO2 generated from the cooking process

scholarly journals Computational fluid dynamics analysis in the ductless whole-house air conditioning system

2020 ◽  
Vol 172 ◽  
pp. 03008
Author(s):  
Rie Tasaka ◽  
Sayaka Kindaichi ◽  
Daisaku Nishina ◽  
Mitsuhiko Maeoki
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Heat Load ◽  
Air Conditioning ◽  
High Energy ◽  
Space Heating ◽  
Cfd Analysis ◽  
Air Conditioner ◽  
Air Conditioning System ◽  
Computational Fluid Dynamics Analysis

Recently, the heat load for space heating in residential houses has been reduced as airtightness, and thermal insulation performance has been improving even in moderate climate regions of Japan. In such situations, the heat load can be handled by one room air-conditioner with high energy efficiency. We report the results of computational fluid dynamics (CFD) analysis of an indoor thermal environment and the airflow distribution during the space heating operation in a ductless house air conditioning system, in which heated air from a room air conditioner installed in a thermal-insulated basement space is distributed throughout the building using air inlets on the floor in each story and open-door rooms without ductworks. To determine the adequate size and position of the air inlets on the floor in this heating system, we evaluated the air circulation performance for changes in the conditions of the air inlets by CFD analysis for a standard two-storey house model in Japan. The results suggest that the air temperature distribution is markedly different in the size and position of the air inlets on the floor. Large volumes of airflow through the openings in the building resulted in maintaining the rooms at a temperature range of 17 to 24 degrees uniformly. These results also provide information for system and building designs for effective space heating and for proper usage when choosing to open or close air inlets in the operational phase.

scholarly journals The Effects of an Air Conditioning System using the Coanda Effect on an Indoor Office Environment

2019 ◽  
Vol 111 ◽  
pp. 01088
Author(s):  
Hitomi Igarashi ◽  
Takashi Akimoto ◽  
Daisuke Hatori ◽  
Shun Kato ◽  
Hikari Sakakibara ◽  
...  
Keyword(s):  
Air Conditioning ◽  
Thermal Environment ◽  
Flow Characteristics ◽  
Heating System ◽  
Residential Area ◽  
Coanda Effect ◽  
Medium Size ◽  
Air Conditioning System ◽  
Net Zero Energy Building ◽  
Coandǎ Effect

In this study, we propose a ductless air conditioning system using the Coanda Effect for a medium size office building to achieve a net-zero energy building (ZEB). The indoor temperature environment and air flow characteristics during cooling and heating conditions created by this system were evaluated. In addition, to validate the computational fluid dynamics (CFD) analysis results when the heating system was activated, the results were compared with the measurement results. The investigation indicated that for cooling, a good thermal environment could be established in the residential area; however, local draught continued to be an issue. For heating, it was confirmed that heating of the residential area could be accomplished using floor suction. In addition, it was shown that the accuracy of the CFD analytical results can be improved by adjusting the input conditions to the actual conditions.

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